The release of UE4.16. A feeling that over UE4 round the clock work crowds of people who, in addition, still do not sleep. And above the Cryengine work 5 drunken guest workers Seriously! What is the point of Crytek to support the engine? No one will choose Cryengine to create his own game when there is a UE4 at hand, developing with leaps and bounds. Yes, the forum has a couple of enthusiasts who have a lot of free time, because they make their game on Cryengine, but it's probably out of habit. Crytek can not interest people, the problem is not only in updates every half a year, the problem is also that the updates do not bring anything that can be touched. PEOPLE LOVE GRAPHICS AND RENDERING! Crytek is needed right now, not half a year later, adding a new Material editor, completely changing Terrain, a new Vertex Blending, etc. People want convenience, flexibility
There is no evidence that full Sandbox sources will be in 5.4 release. Crytek devs mentioned that they will be eventually released but no time frame was given. Roadmap has Sandbox section but you can see only plugin stuff (sample and docs) scheduled for 5.4 and some other bits for 5.5Sandbox source is really good news.